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  • New signals?

    Do you have any plans to produce bracket, splitting and combined home/distant signals?

  • #2
    Two months on from my question, is there any chance of a reply please, Dapol?


    • #3
      "NEW SIGNALS" ?

      Well there is a rumour going around Dapol are considering also producing colour light signals ?

      As I have been building large complex exhibition layouts for decades, that have consistently specialised in the real life methods of operation. I have had to develop some specialised methods of wiring layouts, if realisitc operation is to be acheived. It does of course help having worked on a number of railways including being a train driver, not just in Britain but also overseas.

      One of the primary problems of replicating real life operation on a model railway, is the fundamental real life railway rule "The safe regulation of trains". These mere five words are often totally misunderstood except by qualified railwaymen. But they have massive implications if you want your model railway to work in a real life manner. Signalling is of course a primary part of the "Safe regulation of trains". Indeed NO train can move at any time without the permission or instruction of a signal. The complexities of moving trains in a safe manner, have required a host of "signal" instructions. But as "Multi-aspect" (colour light) signalling is the reason for this little dissertation, I'll stick to this system here.

      Click image for larger version

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      Above: A good example of 3 aspect signals with the original 3 light version of Junction "feathers". This being at the London end of Woking station, and revealing the rear end of a departing 2HAL EMU, on the "Up Slow", The train has not yet "tripped" the green signal to red. The right hand feathers (position 4) are to allow trains to cross to the parallel "Up Fast". To the right can also be seen the "Starter" signal for trains on the "Up Fast". It has to be mounted on a gantry so that the actual signal is to the Left of the train/track it refers too. It too has a "feather" pointing left in what is known as "Position 1". This allowed trains on the Up Fast to cross to the "Up Slow", (the track the EMU is on). The picture also reveals the Up Bay platform track on the extreme left. This track was removed before steam finished in July 1967. More recently they have had to add a new "Up Bay" now located between the Up and Down lines. The "white diamonds" seen on these signals, modified "Section K" of the rule book. "Trains detained on running lines" This altered the "Contact signalman within Two minutes" to "Contact signalman within 8 minutes". The white square with black "X" is simply a sign to show a telephone connected directly to the signalbox. The signal number WV53 on a white background indicates this is a "Controlled signal" not an "Automatic" which wuld have "Auto" added beneath the number. Although the signal automatcially returns to red, the signalman has to release the signal every time. Nearly all signals with "feathers" are of the Controlled type.

      The problems of the 2 aspect type.
      Although colour lights can be said to be simpler than semaphores, there are one or two pitfalls for the unwary. This primarily involves the 2 aspect type. It must be understood that with colour light signals you CANNOT pass a green signal only to find the next is showing a red. A train must be given a warning in the form of a yellow, before reaching the red. So with the two aspect type, a green/yellow 2 aspect "distant" is folowed by a 2 aspect green/red "stop" signal, a mile or so further on. In other words you have to alternate the two types. On a model railway this effectively means you need twice as much space, as two seperate signals are needed. With in total four lights. So three aspect signals effectively work out cheaper, and require less space, and result in THREE lights not FOUR !!!

      The 3 aspect type
      The three aspect type is quite straight forward. Assuming you are driving along a line with three aspect signals spaced roughly at equal distances, you can maintain line speed of your train as long as the signas show green. If you are catching up with the train ahead or possibly approaching a junction you will be given a warning in the form of a single yellow. This tells the driver that for whatever reason he must bring his train under control (start braking) as the next signal is, at that moment, displaying a red. A drivers route knowledge will tell him exactly how far it is to the next signal. It is possible when he comes in sight of the next signal that it might have changed to yellow, implying he is now following a slower moving train. So he continues at caution, again prepared to stop at the next signal should it still be at red. The 3 aspect type is probably the most typical type, as it is suited to most types of line, whether busy or otherwise. It will be spaced accordong to the maximum permitted speed of the line, to allow for adequate braking distance of the worst case scenario train.

      The 4 aspect type.
      This slightly more complex type is normally only encountered approaching larger cities, where density of traffic is now so great as to warrant its use. It allows signals to be spaced somewhat closer together if need be, hand in hand with a lower permitted maximum speed. It is fairly common on Southern Region lines, and found on virtually all routes from the extent of suburban services to the London termini. The addition of an extra yellow light helps to keep trains moving and so reduce brake wear and particularly on the Southern reduce waste of electric power.
      It works like this: A driver proceeds along the line at his permitted speed under the guidance of green signals. The first warning of some sort of delay or hold up, is a "prelimanary warning" in the form of "Two yellows". As in all cases the drivers route knowledge will tell him exactly where the next signal is, whether he can yet see it or not. However he should at the very least shut off power. Knowing the braking behaviour of his train he may begin reducing speed gently. If the blockage ahead has not moved, the next signal will be showing a single yellow, at which point he is certainly going to start braking. Following a single yellow the next signal will be red. The trick with driving Southern EMU's was to try and pace yourself, so that you avoid having to actually stop. Which means bringing the trains speed right down at the single yellow, and coasting gently in the hope the red ahead will change to yellow before you reach it. Trains can coast for miles if handled correctly !

      Colour light Junction signals.
      At Junctions the signal before the junction will most typically have one or more fingers sticking out of its top. A maximum of 6 fingers is possible, with three possible positions on each side of the main signal. The position of the fingers relates to the geographical layout of the junction ahead. So a branch to the left of the mainline will require one finger sticking out of the signal head at 45 degrees. Should there be two possible tracks to the left, this will require two fingers. One at 45 degrees and the next at 90 degrees. The sharpest of the two turnouts is usually the one at 90 degrees. Three lefthand turnouts will result in three fingers to the left of the main signal head at 45, 90 and 135 degrees. In a similar manner any turnouts to the right will have fingers positioned to the right of the main signal head in a similar fashion. Fingers to both the left and right are quite common, depending on the layout and complexity of the Junction. It is rare to see a signal with 5 or 6 fingers. In this scenario if the junction is that complex, the fingers will be replaced by what is known as a "Theatre box" which as its name implies is a box possibly on top or too the left of the signal which can display letters or numbers for which each possible route has been allocated. Drivers route knowledge will tell him what each display means. These are most common entering large stations when most typically the platform number is shown. The "Fingers" refered too, until around 1960 were built with three white lights often refered too in those days as "Lunar lights". Since 1960ish new or replacement signals were fitted with fingers containing 5 white lights, and more recently refered too as "feathers". It must be understood that at such Junctions using fingers, the main straight ahead route does NOT illuminate any of the "feathers". Only when a route to left or right is set, will feathers illuminate.

      Click image for larger version  Name:	Mk1 Sigs K1 & K2 [3].JPG Views:	1 Size:	199.1 KB ID:	7647
      Above: 3 aspect colour light signals (Eckon-Berko heads) mounted on a scratch built gantry. Of a type found on the Southern Regions Waterloo - Bournemouth resignalling scheme in 1965-67. The right hand signal (Up Fast line) has a junction indicator in Position 4 to allow trains to "turn left" onto the parallel "Up Slow". This examples well the problems faced by maufacturers of how to mount signals. This 4 track line has parallel Down and Up lines, not the more typical Up Down Up Down, so requiring a differnt type/size of gantry. .

      One final important point as I have just noticed a manufacturer of colour light signals including something daft in their range. Included in the range were 2 aspect yellow/green signals and 3 aspect yellow/green/yellow (repeater signals) fitted with junction feathers. This is NOT possible as neither of these signal types contain a red. This is possibly a result of confusing the old semaphore signal behaviour of having "Splitting distants" before the actual Junction Home signals. However because the Colour light signal system operates to a totally different set of rules (Track Circuit Block) and Semaphore signals on passenger lines normally to "Absolute Block" rules. Junction colour light distant signals have NO place in reality.

      Other colour light signals.
      Approaching large stations where attaching, dividing,or adding locomotives to trains is usual. Special rules apply. The fundamentals of the colour light system known on passenger lines as "Track Circuit Block", are that this system allows trains to follow each other from colour light signal to colour light signal. Because colour light signals know where each train is thanks to CONTINUOUS track circuits. These same track circuits guarantee that every signal returns to red as a train passes it. So when the second portion of a train is approaching a station where it must join to another portion. It must be brought to a halt at the signal protecting the station platform which is maintained at red.

      Once the signalman is assured that the train has stopped at the red. He can then pull off what is known as a "Calling on" signal. This will be a small triangular box below the main signal head which shows NOTHING until released. When two white lights at 45 degrees are illuminated. This permits him to pass the main signal at red, on the proviso that he proceeds "at a speed no greater than he can see it is safe to bring his train to a halt". He must also stop short of the train he will couple too, and not go straight onto the other portion. This is to ensure no momentum is still inherent in the trains movement. Such calling on signals, allow only passenger trains to be joined, or light locos to attach to their trains. Under no circumstance must freight trains be allowed to mix with passenger.

      Colour light shunting signals often found on the ground are normally again of the triangular box shape, and will contain one red (or a yellow) and two whites (pre1990). From 1990 two reds and one white. Or two yellows and one white. These signals are NOT allowed to be accepted by passenger trains except under special circumstances. The red/white types mean stop when the two lower lights are illuminated horizontally, and permission to pass the signal is permitted when the two diagonal lights are illuminated. The ones with yellow instead of red lights are rarer. These are most frequently found at the exit from a yard, where there is, a "Shunting Neck" or "Headshunt". If a train requires to go into the "Headshunt" it can pass the signal in the restrictive mode. But if it needs to access the main running lines, then it must wait at the signal until illuminated in the diagonal position.

      Such shunting signals are for movement of trains and locomotives excluding ones carrying passengers. They are provided for entrance or exit to/from yards, sidings and depots. And to cover awkward movements by non passenger carrying trains where a main aspect signal is not provided. Such as a light loco having to make a wrong direction move to get around its train within station limits.

      Not quite exhaustive but the above covers the most important types, and the method of their operation, with regard to "Track Circuit Block" lines. Rules on single track lines, such as "Electric Token Block"; "No signalmans Token Block" "Radio Electric Token Block" or freight only lines operating under such systems as "C2" lines can be totally different.

      Modelling Colour light signals.
      I won't stick my neck out and recommend any current model products. Except to say that if DAPOL can produce colour light signals that look a little better than the commercial products currently available, and do them at somewhere near the price of their current semaphores, I reckon they could sweep the floor with the competition.

      Click image for larger version  Name:	Mk1 Sigs K1 & K2 [07].jpg Views:	1 Size:	486.6 KB ID:	7648
      Above. Another shot of the same signal as seen above, but a few months later when scenery had begun appearing. Note the rear of another signal on the 2 track "Salisbury" line. That also had a junction "feathers" as these two routes joined a few feet behind the camera. Picture taken around 2010

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      Above: King Arthur N15 class 4-6-0 30764 "Sir Gawain", stopped at signals. This particular gantry is a "Model Signal Engineering" modified etched brass structure redesigned to take colour lights instead of semaphores. Such alterations actually occured on the Waterloo-Bournemouth line if the gantry was suitably positioned for colour lights, during resignalling in 1965-67.

      Signalling it should be admitted is a minefield for a commercial player. As there are just so many methods of mounting colour light signals. My huge exhibition layout Basingstoke (87ft x 24ft) needs around 38 x 3 aspect signals, 23 colour light shunting signals and a host of semaphores. The problem of the 3 aspect types, is that they need to be mounted in pairs on signal gantries, as exampled in the photos. Of course that's just the first problem for a manufacturer.

      The problems of wiring signals to work correctly !
      The next consideration is what system of wiring to provide. Choosing a system exclusive to DCC is not clever as all comers can be accomodated. Secondly having just discovered a new colour light signal product from a newish accessory manufacturer. The wiring system provided to suit DCC, actually prevents the signal from being operated correctly, simply because the manufacturer seems to be under the impression only two wires are acceptable. The sensible approach I would say is to provide a system anyone can use, that also permits correct operation. And also allows DCC fans to plug the signal (however many wires it needs) into a DCC actuation board where the complexity of accurate operation can be automated in "plug and play" fashion.

      Because I'm building a large exhibition layout (Basingstoke 1958-67, 87ft x 24ft) for use on virtual permanent display at the "Mora la Nova" Railway Museum near Tarragona. It is paramount that the layout can demonstrate accurately the full workings of British signalling exactly as in reality for the period chosen. Being a Railway Museum, automated toy train sets, such as the tourist attraction layout in Hamburg is exactly what the Museum Curator insists he will NOT accept. Everything, even the timetable and train formations must be exactly correct for the period. Indeed the Curator has just gone to the expense of having "tracksetta" type tools made so that model points up to 5 metres (16ft) radius can be accurately built in both OO and HO scales. ( A second Spanish HO layout is also now under construction as we have a lot of space).

      Many years ago I sat down with the then British Railways Southern Region Central Division, Chief Signalling Engineer. This was to plan a way of replicating exactly on a model railway how multi-aspect signalling works in real life. The starting point was how to recreate "Track Circuits" cheaply and easily, which are a MUST HAVE, if you want the signals to work correctly. Next was what products we could use, that would keep the price of signalling large layouts within the clubs budget. The methods to be used required signals to change back to red as a train passed, and then change to yellow once the train had competely passed the next signal up the line, and green when it had passed the signal after that, just as in real life. The signals also had to be capable of being "interlocked" with other signals and pointwork to ensure clear aspects could not be shown if the route was not set up. Further to prevent club members crashng other members often very valuable hand made locos and rolling stock, we added an "AWS" (Automatic Warning System), to prevent trains crashing red signals. After a few club nights bouncing various methods and ideas about. We settled on a system that uses nothing more complex than 12v DC relays, the odd diode (electrical one way gate), and when LED's replaced "Grain of wheat bulbs" a few "1K" resistors to reduce 12v DC to 1.8v for the LED's benefit.

      The resulting system went onto club layouts, and all my own personal exhibition layouts that I have built ever since. Indeed despite the arrival some years ago of Digital Command Control (DCC) and its potential to provide real life type signalling and junction operation, including complete "interlocking". The only facilities available so far bear NO resemblence to real life, with potty ideas such as signals changing after an amount of time....

      So Below I have added a wiring diagram of the wiring needed for a pair of totally automatic 3 aspect signals that operate in conjunction with "Track circuits" to ensure totally accurate real life type operation. Being a four track mainline, the two signals shown are for parallel "Up Fast" and "Up Slow" lines. So only half the number of relays and wiring seen, would be needed on a normal two track line. The AWS feature mentioned above, is not included for clarity, but simply utilises the spare swiitch on the Signal relays seen. So that when the signal is not showing a red, it will automatically energise an otherwise dead section of track, about two coaches long, immediiately beyond each signal.

      The signals illustrated in the wiring diagram are actually the "Up Outer Homes" for Hook station (One stop nearer to London from Basingstoke). They can be fully automatic as no pointwork is involved requiring interlocking. These fully automatic signals therefore are connected to the previous pair of signals as well as the next pair up the line. Hence the wiring leading in from the right, is exactly the same as the wiring leading off the page to the left. The signals are numbered S6 (Slow line) and F6 (Fast line) and all the relays have similar numbers to show to which signals they are either fully or partialy working with.

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      Above: A wiring diagram for a pair of parallel 3 aspect fully automatic signals that work EXACTLY as their real life counterparts south of Hook Station do. No switches necessary only 3 relays and some wire for each signal, which includes the stupidly simple track circuits. Only the signal wiring is shown. Everything on my layout uses 12v DC as mixing AC and DC on one layout is asking for problems with exhibition layouts, and greatly increases wiring. Everything electrical on the layout (over 800 items) all uses the same "ONE" common return wire, saving 799 bits of wire or around 1 mile of cable on this layout with its circumference of about 255ft !

      The Duke 71000
      Last edited by The Duke 71000; 2 August 2018, 14:51. Reason: Added prototype signal photo with useful modelling info about such signals.